Photographic-printing process



UNITED STATES PATENT OFFICE.

JOHN EDWARD THORNTON, OF WEST HAMPSTEAD, LONDON, ENGLAND, ASSIGNOR TOJOHN OWDEN OBRIEN, OF MANCHESTER, ENGLAND.

PHOTOGRAFHIG-PRINTING PROCESS.

.Patented Feb. 28, 1922.

No Drawing. Original application filed March 21, 1916, Serial No.85,702. Divided and this applica- To all whom it may concern:

Be it known that I, JOHN EDWARD THORN- TON, a" British subject, residingat lVest Hampstead, London, England, have invented certain new anduseful Im rovements in and Relating to Photographicrinting Processes, ofwhich the following is a specifica- -t1on.

This invention relates to the production of kinematograph films.

The object of the invention is to prepare a printing belt or beltsbwhich transparent kinematograph films 0 continuous 1ndefinite lengthcan be produced by mechanical printing of the pictures thereon withapplied inks or colours" as distinct from printing photographicallyWithsensitive chemical media, acted upon by light, and as distinct fromapplying colour to a photographically printed series of pictures. y

The original picture film of continuous indefinite length isphotographed in the ordinary way and fromrthis the one or more printingbelts are prepared by any of the processes known in photo mechanicalprinting such as photo-aquatint, mezzotint, mezzotype, collotype orprocesses analagous to photo lithography by which a plain or levelprinting surface isiobtained on a material having an atlinity for a.greasy printing ink interspersed with portions having an afiinity to aliquid such as water or glycerine or other suitable moisture repellentto greasy ink. v

Photo-mechanical printingis defined as follows :-The actual operation ofprinting requires neither the use of a sensitive surface nor the actionof light, nor subsequent development. Instead of such methods printingis effected by mechanical pressure of the film against a plate (in theform of a continuous belt) which has been prepared with a series ofimages by one of the photomechanical processes. y

The medium used to form the image is therefore a printing or applied inkor colour instead of a. sensitive salt. Various kind; inks or colourscan be used according to the particular type of en raved or otherprintin plate (herein. terme printing belt) use I prepare a strip orband of copper, steel, brass, aluminum or other metal, or a strip ofgelatine. the gelatine being on a supporttion filed July 5, 1919. SerialNo. 309,427.

ing base, or a strip of celluloid with a coating of gelatine or othercolloid, prepared with a sensitive surface in any of the methods wellknown for photo-mechanical rinting to receive an impression of theoriginal picture film.

The prepared strip which is to form the printing belt is perforated ornotched along its margins or centre to correspond precisely with. theperforations or notches in the camera film and in the transparentkinematograph film of indefinite length.

Upon the prepared strip I produce a mechanical printing surface(hereinafter referred to ass. printing belt) comprising a surfacedivided into a number of broken tone margins of 'fine lines, dots, orother markings, having an affinity for greasy printing ink andinterspersed with spaces having an ailinity for moisture, which whenmoistened will repel the greasy printing ink.

The gradations of light and shades are produced by "varying the relativesizes or areas of the two parts of the printing surface.

In preparing printing belts from the original picture film moreparticularly of the individual elemental colours two or more of suchprinting belts may he made from each, one lightly exposed for the denseparts and. the other fully exposed for the lighter tones. By printingfrom one or otherof these printing belts or from both in succession ahigh degree of tint is reached and desirable or Special effects forharmonizing harshness or other defects becomes practicable. Or one of,such printing belts may be used for printing say alight shade or tone ofblue or a greenish blue, and another for printing a deep blue or apurple blue to give better offeet to the colours in the picture. Thismode of operation is regarded as of special importance in relation tooriginals produced by the two-colour process.

These surface processes include all the variations that come under thehead of planographic processes, which depend upon the opposition of animage in fatty ink to moisture, such as collotype, photo-litho,zincwashed to remove surplus bichromate. It is then treated withglycerine or various moisture-retainin solutions which are absorbed bythe soi t gelatine portions of the image not affected by light andrepelled by the hardened light-affected portions. \Vhen ink or colour isthen applied b inking rolls, the ink adheres only to the ry parts and isrepelled by the damp portions. It is then transferred to the film bypressure. Such a printing belt can be made of celluloid or metal. Forphoto-litho, zincography, algraphy and the like processes a grainedmetal belt is used, though in certain circum stances grained celluloidmay be substituted.

For the collotype process the printing belt may be either metal,celluloid or other waterproof material coated with a layer of gelatineor other colloid of a hard kind and to promote the adhesion of thegelatine the band may be corrugated grooved perforated or roughened. Oras a preferied method, the band may be stamped or cut with numeroussmall and closely grouped slits or perforations into which the gelatinewill penetrate.

A printing belt prepared by the collotype' rocess as above described,has advantages in relation to the subsequent printing of thekinematograph film therefrom, in that a stiff water colour or waterglycerine colour may be used instead of the usual fatty or printers ink,as described in the eleventh article of a series of articles on photocollotype in the British Journal of Photography for 1879; this eleventharticle commencing on page 410 of the volume, and the description of theof stiff water colour inks being on page In the preparation of printingbelts when printing through the screen it is desirable that the screenshould be moved slightly relatively to the belt-either laterally orlongitudinally or both 'after each individual picture is exposed, sothat the dots or points or lines on the printing surface of the printingbelt, and subsequently the dots, points or lines printed therefrom uponthe kinematograph film, will not fall in the same place in thesuccessive pictures, and so, owing to the rapidity of projection and thepersistence of vision, such dots or points will not be visible on theenlargement when projected upon a sheet or screen, the picture appearingas full tone grainless picture.

The kinemtogmph flZm.--The strip or film upon which the pictures are tobe printed from the printing belts to pmduce the finished kinematographfilm may be of the ordinary celluloid material now employed forkinematograph films or any other transparent film material.

Mechanical printing of lcimmatogmph films.-In the mechanical printing ofthe films from the printing belts herein de- LADB ,314

scribed any suitable ink or colour may be employed that is adapted tothe particular form of printing belt and the surface of the film uponwhich the print is to be made.

To prevent or minimize adhesion of the damp gelatine the receivingsurface may be coated or sprayed with animal bile, or a solution of thecommercial purified ox-gall. The printing may be done by applying theink to the printing belts by any well known printing method such as by aroller. The printing belts with perforations along'their margins inwhich registering pins can operate, and the film also similarlyperforated, are drawn together between rollers or pressing surfaces bywhich contact or pressure will be applied picture by picture. Sprocketteeth or claws are fitted to draw the two through the machine in correctregister.

W'hat I claim as my invention and desire to protect by Letters Patentis 1. A photo-mechanical printing belt for the production of continuousindefinite lengths of kinematograph positive film pictures, providedwith perforations and a series of printing cliches formed on the surfaceand bearing pictures arranged in succession longitudinally thereon, eachclich bein capable of printing a half tone image with all the gradationof a photograph by planographic methods, the chch consisting of alargenumber of fine broken-tone markings, having an affinity for greasyprinting ink, and the blank spaces between having an afi'mity for andbeing charged with a moisture repellent to greasy ink, and'thegradationof image being formed by making the said printing dots, lines,or mosaic of varying size and area, so that they are capable ofdepositing varying areas of ink and thus forming a series of printedimages of full gradation by the agency of applied ink and pressure andby planographie printing methods.

2. A series of perforated photo-mechanical printing belts for producingcontinuous lengths of kinematograph positive films as inclaim 1, forprinting the main part of each image by one printing belt, andintensifying parts of each image by printing from other printing belts,the corresponding parts of each image of the series being different ininkarea for each belt, and requiring the printing from all belts insuccession to complete the series of images and to difl'erentiallyintensify each image of the series.

3. A series of perforated photo-mechanical printing belts for producingcontinuous lengths of kinematograph positive films, by means of a largenumber of fine brokentone markings forming printing points of varyingsize and area, having greasy ink attracting character with interveningspaces of water-absorbin and greasy ink resisting character, as in c aim1, the said printing points having their incidence varied in rela tionto the particular part of the picture image upon every printin belt ofthe series, in order that the grain of the picture may be obliterated bythe successive printings and thus form a series of full-tone grainlessfilm pictures by applied ink, and pressure and superimposed printingsand planographic printing methods.

4. series of perforated photo mechanical printing belts for producingcontinuous lengths of kinematograph positive prints in multi-colourheliochrome, by means of a large number of fine broken-tone markingsforming printing points of varyingsize and area as in claim 1, eachcolour of the composite heliochrome being formed upon a separate belt,which colors aresubsequently printed on to the film by superimposedplanographic printing, andby applied ink and pressure, to producecomplete heliochrome continuous positive films.

5. A series of perforated photo-mechanical printing belts for producingcontinuous lengths of kinematograph positive prints n multi-colourheliochrome, by means of a large number of fine brokemtone markings orprinting points of varying size and area as in claim 4, the com siteheliochrome being split into a plurality of printings of each colour andeach being printed from a different belt in which the printing pointshave their incidence varied in relation to the same particular part ofthe picture image, in order that the grain of one printing may beobliterated by the second printing of the same section of the picture,with the object of producing when the remaining colours of the imageseries have been similarly split and applied a series of grainlessfull-tone heliochrome kinematograph positive film pictures, by appliedink and pressure and superimposed planographic printings.

6. A continuous planographic printing belt as in claim 1, having itsprinting clichs produced by relief methods, in a large number of finebroken-tone markings of varying size and area, which receive varyingquantities of greas ink according to their varying areas, an yield it toan absorbent film surface by means of applied pressure, the

.so that they are capable of de image being formed by making the said.

printing points of varying size and area,

ing areas of ink to form pictures in the form of a continuous seriesupon a continuous indefinite length of kinematograph film.

9. A continuous printing belt as in claim 1, having its printing clichsproduced by planographic methods, in a series of markings of varyingarea, having greasy-inkattracting character with intervening spaces ofwater-absorbing and greasy-inkresisting character which receive varyingquantities of ink according to their varying areas, and yield it to anabsorbent film surface by means of applied pressure and planographicprinting methods.

10. A definite length with planographic clichs thereon, formed withholes in'its bod that are filled with gelatinous spongy lling, which isalso continued on to the back and front parts of the belt, to act as amoisture feed, fountain by which moisture applied to the back of thebelt whilst it is moving is gradually fed through the belt to the porousportions of the clichs attached to its face, when used for printingkinematograph films by planographic processes.

In testimony whereof I have hereunto set my hand in presence of twosubscribing witnesses.

JOHN EDWARD THORNTON. Witnesses:

J. Owmm OBmmv,

\V. A. Hoaswon'rnr.

ositing vary- I continuous printing belt of in-

